Background: The extent to which volume spacers may influence systemic activity of inhaled beclomethasone dipropionate (BDP) has not been evaluated.

Aim: To assess whether the AeroChamber Plus (TM) spacer is equivalent to the Volumatic (TM) spacer for administration of inhaled hydroflouroalkane 134a propelled BDP in terms of lower leg growth rate (LLGR).

Patients and Methods: Prepubertal children with mild asthma (n = 26, aged 6-14 years) were included in a 3-time periods of 2 weeks duration randomised, double-blind, crossover study with a single-blind placebo run-in and two washout periods.  LLGR was measured with the knemometer.  Interventions were inhaled BDP hydroflouroalkane 134a pressurised metered dose inhaler 100 microg and 200 microg bid with the AeroChamber Plus and 200 microg bid with the Volumatic spacer.

Results: Beclomethasone dipropionate 200 microg bid from the AeroChamber Plus was non-inferior to BDP 200 microg bid from the Volumatic spacer as the lower margin of confidence interval of the difference between treatments (-0.18 to 0.13 mm/week) was greater than the prespecified lower limit for non-inferiority (-0.20 mm/week).  UFC/creatinine data showed no statistically significant variations.

Conclusions: The systemic activity of BDP is similar via the Volumatic and AeroChamber Plus spacers.  The AeroChamber Plus spacer may be used in children without risk of increasing systemic activity of BDP.